Export private keys from HD wallet addresses (#3253)

### What

Let's allow exporting private keys from HD wallet addresses.

### Testing

- [x] add HD wallet with the mnemonic
- [x] export private key for account from HD wallet
- [x] export the same private key with metamask and compare them


![image](https://user-images.githubusercontent.com/20949277/231476213-bc482747-a91d-4a18-9eed-21254db91e0c.png)


Latest build:
[extension-builds-3253](https://github.com/tahowallet/extension/suites/12348519892/artifacts/655435412)
(as of Wed, 19 Apr 2023 17:38:25 GMT).

background/package.json

@@ -39,7 +39,7 @@
     "@ledgerhq/hw-transport": "^6.20.0",
     "@ledgerhq/hw-transport-webusb": "^6.20.0",
     "@redux-devtools/remote": "^0.7.4",
-    "@tallyho/hd-keyring": "0.4.0",
+    "@tallyho/hd-keyring": "0.5.0",
     "@tallyho/provider-bridge-shared": "0.0.1",
     "@tallyho/window-provider": "0.0.1",
     "@types/w3c-web-usb": "^1.0.5",

background/services/keyring/index.ts

@@ -581,8 +581,16 @@ export default class KeyringService extends BaseService<Events> {
     this.requireUnlocked()
 
     try {
-      const privateKeyWallet = await this.#findPrivateKey(address)
-      return privateKeyWallet.privateKey
+      const signerWithType = await this.#findSigner(address)
+
+      if (isPrivateKey(signerWithType)) {
+        return signerWithType.signer.privateKey
+      }
+
+      return signerWithType.signer.exportPrivateKey(
+        address,
+        "I solemnly swear that I am treating this private key material with great care."
+      )
     } catch (e) {
       return null
     }

background/services/keyring/tests/index.unit.test.ts

@@ -134,13 +134,6 @@ describe("Keyring Service", () => {
 
       expect(keyrings.length).toBe(1)
     })
-    it("should be able to export mnemonic", async () => {
-      const mnemonic = await keyringService.exportMnemonic(
-        HD_WALLET_MOCK.addresses[0]
-      )
-
-      expect(mnemonic).toBe(HD_WALLET_MOCK.mnemonic)
-    })
     it("should be able to sign transaction", async () => {
       const address = HD_WALLET_MOCK.addresses[0]
       const signed = await keyringService.signTransaction(
@@ -203,13 +196,6 @@ describe("Keyring Service", () => {
       })
       expect(keyringService.getPrivateKeys().length).toBe(1)
     })
-    it("should be able to export private key", async () => {
-      const privateKey = await keyringService.exportPrivateKey(
-        PK_WALLET_MOCK.address
-      )
-
-      expect(privateKey).toBe(PK_WALLET_MOCK.privateKey)
-    })
     it("should be able to sign transaction", async () => {
       const { address } = PK_WALLET_MOCK
       const signed = await keyringService.signTransaction(
@@ -245,4 +231,53 @@ describe("Keyring Service", () => {
       expect(signed).toBeDefined()
     })
   })
+
+  describe("export secrets", () => {
+    beforeEach(async () => {
+      await keyringService.importSigner({
+        type: SignerTypes.privateKey,
+        privateKey: PK_WALLET_MOCK.privateKey,
+      })
+      await keyringService.importSigner({
+        type: SignerTypes.keyring,
+        mnemonic: HD_WALLET_MOCK.mnemonic,
+        source: "import",
+      })
+    })
+    it("should be able to export private key", async () => {
+      const privateKey = await keyringService.exportPrivateKey(
+        PK_WALLET_MOCK.address
+      )
+
+      expect(privateKey).toBe(PK_WALLET_MOCK.privateKey)
+    })
+    it("should be able to export mnemonic", async () => {
+      const mnemonic = await keyringService.exportMnemonic(
+        HD_WALLET_MOCK.addresses[0]
+      )
+
+      expect(mnemonic).toBe(HD_WALLET_MOCK.mnemonic)
+    })
+    it("should be able to export private key from HD wallet addresses", async () => {
+      const privateKey = await keyringService.exportPrivateKey(
+        HD_WALLET_MOCK.addresses[0]
+      )
+
+      expect(privateKey).toBe(PK_WALLET_MOCK.privateKey) // first address from both mocks is the same
+    })
+    it("should require wallet to be unlocked to export secrets", async () => {
+      keyringService.lock()
+
+      const errorMessage = "KeyringService must be unlocked."
+      const exportMnemonic = async () => {
+        await keyringService.exportMnemonic(HD_WALLET_MOCK.addresses[0])
+      }
+      const exportPrivateKey = async () => {
+        await keyringService.exportPrivateKey(PK_WALLET_MOCK.address)
+      }
+
+      expect(exportMnemonic()).rejects.toThrowError(errorMessage)
+      expect(exportPrivateKey()).rejects.toThrowError(errorMessage)
+    })
+  })
 })

ui/components/AccountItem/AccountItemOptionsMenu.tsx

@@ -16,6 +16,12 @@ type AccountItemOptionsMenuProps = {
   accountType: AccountType
 }
 
+const allowExportPrivateKeys = [
+  AccountType.PrivateKey,
+  AccountType.Imported,
+  AccountType.Internal,
+]
+
 export default function AccountItemOptionsMenu({
   accountTotal,
   accountType,
@@ -35,25 +41,9 @@ export default function AccountItemOptionsMenu({
     dispatch(setSnackbarMessage("Address copied to clipboard"))
   }, [address, dispatch])
 
-  const getCustomOptions = useCallback(() => {
-    switch (accountType) {
-      case AccountType.PrivateKey:
-        return isEnabled(FeatureFlags.SUPPORT_PRIV_KEYS)
-          ? [
-              {
-                key: "key",
-                icon: "icons/s/key.svg",
-                label: t("showPrivateKey.header"),
-                onClick: () => {
-                  setShowPrivateKeyMenu(true)
-                },
-              },
-            ]
-          : []
-      default:
-        return []
-    }
-  }, [accountType, t])
+  const canExportPrivateKey =
+    isEnabled(FeatureFlags.SUPPORT_PRIV_KEYS) &&
+    allowExportPrivateKeys.includes(accountType)
 
   return (
     <div className="options_menu_wrap">
@@ -142,7 +132,18 @@ export default function AccountItemOptionsMenu({
               copyAddress()
             },
           },
-          ...getCustomOptions(),
+          ...(canExportPrivateKey
+            ? [
+                {
+                  key: "key",
+                  icon: "icons/s/key.svg",
+                  label: t("showPrivateKey.header"),
+                  onClick: () => {
+                    setShowPrivateKeyMenu(true)
+                  },
+                },
+              ]
+            : []),
           {
             key: "remove",
             icon: "garbage@2x.png",

yarn.lock

@@ -3300,10 +3300,10 @@
   dependencies:
     defer-to-connect "^1.0.1"
 
-"@tallyho/hd-keyring@0.4.0":
-  version "0.4.0"
-  resolved "https://registry.yarnpkg.com/@tallyho/hd-keyring/-/hd-keyring-0.4.0.tgz#0b78b5f60aa625862a8c54b136a3c934fe67d9df"
-  integrity sha512-IEJHyXAN3XSc3wUy6uEF6MiEpK3wjM63pMSS9uD/uG3c6zWpcGVJz7LxnIBSXo2KBiSXKY5Rr/nMud5PcrcddA==
+"@tallyho/hd-keyring@0.5.0":
+  version "0.5.0"
+  resolved "https://registry.yarnpkg.com/@tallyho/hd-keyring/-/hd-keyring-0.5.0.tgz#e65b54fa3b5e0ef2020440d4b87b0f0a4e481bf0"
+  integrity sha512-AmqDNuFYzbYH78slTi8EykmBJd/2dhXDT0VWS/x6dsiR6XaAhuYR17YW/oyseAsTRC0OSdjUs8APxs4BGhLdfw==
   dependencies:
     "@ethersproject/abstract-provider" "5.6.1"
     "@ethersproject/abstract-signer" "5.6.1"